Do fish feel pain?

[FlatAssembler]

I don't see how or why a fish (or any other creature) wouldn't feel pain, it's a basic response to avoid harmful things

Well, like I've said, fish don't have the anatomical machinery that seems to be necessary to feel pain. Sharks and sterlets don't even have nociceptors. And higher fish, while they do have nociceptors, they have little or no type-c neurofibers, which seem to be necessary for pain (Although some experts argue that, in higher fish, type-A-delta neurofibers play the same role as type-C neurofibers do in birds and mammals). As well, fish don't behave as if they felt pain. A fish with a hole in its fin continues swimming normally, for example.